How to encrypt an email in Outlook
Outlook has two kinds of encryption: Microsoft's built-in message encryption (the Encrypt button) and S/MIME certificates. Most people want the first one.
In new Outlook, Outlook on the web or Outlook.com: start a new message, choose Options › Encrypt, then pick Encrypt (or Encrypt-Only) or Do Not Forward, and send. In classic Outlook, use Options › Encrypt the same way. Encryption needs a Microsoft 365 plan that includes it, or a Microsoft 365 Personal or Family subscription for Outlook.com.
New Outlook for Windows and Outlook on the web
- Click New mail.
- Select the Options tab.
- Click Encrypt.
- Choose Encrypt-Only (encrypted; the recipient can still forward or copy) or Do Not Forward (encrypted, and the recipient cannot forward, print or copy).
- Write the message and click Send.
Outlook.com (with Microsoft 365 Personal or Family)
- Start a new message.
- Choose Options › Encrypt.
- Pick Encrypt or Do Not Forward.
- Send.
To remove encryption before sending, choose No permission set. With Do Not Forward, Word, Excel and PowerPoint attachments stay protected after download, but PDFs and images do not.
Classic Outlook for Windows
One message: in a new email, go to Options › Encrypt and choose the protection you want.
S/MIME (certificate) encryption: if your organization uses digital certificates:
- Go to File › Options › Trust Center › Trust Center Settings › Email Security.
- Under Encrypted email, click Settings, then use Choose to pick your certificate.
- To encrypt everything you send, tick Encrypt contents and attachments for outgoing messages.
S/MIME only works when both you and the recipient have certificates and an email app that supports S/MIME.
What the recipient sees
- Outlook and Microsoft 365 users usually read it like any other email.
- Gmail, Yahoo and others get a message with a link. They sign in or request a one-time passcode by email to read it.
Which plans include Outlook encryption
- Included: Microsoft 365 Business Premium, Microsoft 365 E3/E5, Office 365 E3/E5, and education and government A and G plans.
- Needs an add-on (Azure Information Protection Plan 1): Business Basic, Business Standard, Office 365 E1, F3 and Exchange Online plans.
- Home users: Outlook.com encryption is part of Microsoft 365 Personal and Family subscriptions.
Don't see an Encrypt button? Your plan probably does not include it, or your IT admin has not turned it on.
Steps checked against the official help pages in October 2026. Menus move from time to time; if yours looks different, tell us.
Questions people ask
- Is Outlook email encrypted by default?
- Messages are protected in transit between servers that support TLS, but they are not end-to-end encrypted unless you use Encrypt or S/MIME.
- Can someone with Gmail read my encrypted Outlook email?
- Yes. They get a link and verify with a one-time passcode or by signing in.
- What is the difference between Encrypt and Do Not Forward?
- Encrypt protects the message. Do Not Forward also stops the recipient forwarding, printing or copying it.
Sending one email to a whole list? Check the addresses first with Veml, which removes bad and risky emails before you hit send. (Veml and EmailNa have the same owner.)